Cycloolefin (co)polymers are characterised by many advantageous properties, including a high transparency for use for optical applications. They have a good thermal stability, ageing resistance, chemical resistance, good gas barrier properties, solvent resistance, low water absorption, high scratch resistance, low double refraction and high softening temperatures (glass transition temperatures Tg). Such (co)polymers are therefore suitable for, inter alia: films in unstretched or monoaxially or biaxially stretched form for packagings and as cover layers for polarisation films and liquid crystal displays, as materials for optical data storage media, lacquer constituents, for example for the automobile industry in order to render surfaces scratch resistant; fibres, for example for light-conducting fibres, optical lenses and prisms; flexible hoses, tubings, rods, bars and carrier plates; cover discs for solar cells; capacitor dielectric material. Such technical articles are produced by injection moulding or extrusion. The (co)polymers that are used are amorphous or only partially crystalline. The (co)polymers may be employed alone or mixed with other polymers.
The polymerisation of cyano-substituted norbornene derivatives is in principle known from DE-A-2 316 087. As catalysts for the ring-opening polymerisation of the norbornenes there are used tungsten and molybdenum compounds, in particular their halides, in combination with aluminium alkyls. No metal-carbyne complexes are disclosed. The Ziegler-Natta catalysts disclosed here are not sufficiently active in the presence of polar groups.
U.S. Pat. No. 4,039,491 discloses norbornene polymers and copolymers produced from norbornene monomers using tungsten and molybdenum compounds and organometallic compounds of Groups 1, 2, 12 and 13 of the Periodic System according to IUPAC 1985. No metal-carbyne complexes are disclosed. The Ziegler-Natta catalysts disclosed here are not sufficiently active in the presence of polar groups.
U.S. Pat. No. 5,312,940 discloses cycloolefin polymers and their production using metal-carbene complexes as catalysts. Metal-carbyne complexes are not mentioned. In addition, the disclosed carbene complexes are complicated to synthesise.
DE-A1-199 15 275 also discloses cycloolefin polymers and their production using metal-carbene complexes as catalysts. Here too metal-carbyne complexes are also not mentioned. The disclosed carbene complexes are also difficult to synthesise.
K. Weiss, R. Goller, M. Denzner, G. Löβel, J. Ködel in Transition Metal Carbyne Complexes, (Editor: F. R. Kreiβl), Kluwer, Dordrecht, 1993, 55, disclose the polymerisation of non-polar substituted cycloalkenes using tungsten-carbyne complexes. The polymerisation of polar substituted cycloalkenes is not described.